A critical appraisal of the toxicological aspects of COVID-19 and its vaccines

In December 2019, a new viral strain occurred in Wuhan, China, that rabidly took over the globe resulting in the most impactful pandemic of the last 100 years. Soon, the viral strain was identified as a member of the coronaviridae family; the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and the associated disease was named coronavirus disease 19 (COVID-19). Understanding the virology of this new pathogen and creating effective vaccines and treatments became the foundation of the research efforts to control the pandemic. COVID-19 has demonstrated high levels of transmissibility and significant morbidity and mortality. Vaccines for COVID-19 were developed at an unprecedented speed. While concerns about vaccine safety were widely shared, the COVID-19 vaccines generally proved safe and effective. However, as the virus spread across the globe, it soon became evident that various strains could rise and dominate. Indeed, although a large portion of the global population has been vaccinated, infectiousness remained high, with some mortality decrease. Thus, re-appreciation of SARS-CoV-2 toxicodynamics, infection profiles, and summarization of the available vaccines is still needed to understand possible individual and/or environmental predispositions explaining these trends. Here, we provide a framework to evaluate the toxicology of the many COVID-19 vaccines in light of COVID-19 and its variants. In summary, the COVID-19 vaccines remain safe, effective, and thus recommended even in light of the reduced effectiveness of the vaccine due to the variants.